Furnace wall



FURNACE ALL June 2, 1

Filed Oct. 19

1928 3 sheets -sheet l INVENTOR O. NYGAARD June 2, 1931.

FURNACE WALL Filed Oct. 19. 1928 3 Sheets-Sheet 2 mvmToR 14/ TTORNEY 0. NYGAARD June 2, 1931.

FURNACE WALL Filed Oct. 19. 1928 3 Sheets-Sheet 3 INVENTOR Patented June 2, 1931 UNITED STATES OSCAR NYGAARD, OF SAUGUS, MASSACHUSETTS FURNACE WALL Application filed October 19, 1928. Serial No. 813,455.

This invention relates to furnace walls which are subjected in whole or in part to extreme, and at times uneven, temperatures, and more particularly to the construction of inner facings or linings therefor.

In my application led February 4, 1926, Serial N 0. 85,916, I have disclosed an inner facing or lining for a permanent furnace wall which is suspended therefrom in a novel manner. The inner facing is composed of units small enough to be manufactured cheaply and be handled practically in assembling and repairing the facing. A characteristic feature of this facing resides in the means for supporting said units in spaced relation, both vertically and horizontally, to provide for free expansion of each unit independently of each other unit. For practical reasons it is preferable, but not essential within the scope of the invention disclosed in said application, that the unit comprise two bricks one of which is suspended from the permanent inner wall of the furnace and the other one of which is supported entirely by the suspended brick. The supported brick in one unit and the suspended brick in a unit adjacent thereto are separated by a horizontal space to provide for free vertical expansion. This vertical expansion joint is sealed by overlapping rabbeted edges on the supported brick in one unit and the suspended brick in another unit.

The principal object of the present invention is, generally, to provide the facing disclosed in my application hereinbefore identified with an improved flexible joint for taking care of vertical expansion.

To the accomplishment of this object, a feature of the invention contemplates the provision in a furnace wall construction aving a permanent wall, a facing therefor, and means on the inner permanent wall engaging the top and bottom of the facing of sections in said facing at least one of which engages the section immediately above it and immediately below it on inclined plane surfaces whereby said sections shift relatively on said surfaces to maintain the height of the facing substantially constant during furnace temperature changes.

Broadly considered the inclined plane surfaces upon which the adjacent sections shift relatively may extend entirely across the depth of the sections. But owin to the obliquity of the inclined plane sur ace such a section would taper to a sharp edge which might possibly become broken during manufacture, packing, shipping or handling in assembling or repairin the facing. It is preferred, therefore to limit the width of the inclined plane surfaces to less than the depth of the sections and provide a space between the opposite portions of the sections adjacent the inclined plane surfaces to allow the sections to so move relatively. Specifically, abutting inclined plane surfaces are provided on the supported brick in one unit and on the suspended brick in another unit adjacent thereto.

In addition, as will be readily understood by those skilled in the art from the following description, further features of the present invention comprise the novel constructions, arrangement and combination of parts for furnace walls hereinafter described in their preferred form and then particularly pointed out in the appended claims.

The various features of the invention will be best understood from a description of the best form at present known to me, illustrated in the accompanying drawings, in which:

Figure l is a view, in erspective, of a portion of a masonry wall or furnaces lined with an inner facing, the air circulation between the facing and the permanent inner wall being through horizontal passes;

Fig. 2 is a view of several tiers of the wall in vertical section;

Fig. 3 is a sectional Fig. 2;

Fig. 4 is a sectional plan on the line 44, Fig. 2;

Fig. 5 is a sectional Fig. 2;

Fig. 6 is a sectional elevation same general characteristics of plan on the line 5-5,

having the the wall illustrated in Fig. 1, the air circulation beplan on the line 33,

tween the facing and the permanent wall being through vertical passes;

Fig. 7 is a sectional elevation of the vertical pass furnace wall;

Fi 8 is a sectional plan on the line 88, Fi

Fig. 9 is a sectional plan on the line 9-9, Fi i Figs. 10 and 11 are views, in perspective, of the two preferred types, of inter-engaging suspended brick aprons used in buildingz the facing, and

igs. 12 and 13 are views, in perspective, of the two preferred types of inter-engaging tiller brick that form intermediate tiers between the tiers of suspended or apron bricks.

In the embodiment of the invention illustrated in the drawings 14 (Figs. 1 and 2) indicates the permanent furnace wall having an inner surface 15, an overhanging top 16, and a projecting bottom 17. Interposed between the overhanging top 16 and the projecting bottom 17 and spaced from the inner surface 15 is a refractory inner facing or lining 18 which covers said inner surface from top to bottom. The inner facing 18, in addition to engaging the top 16 and bottom 17, is removably supported from the permanent wall 1-1. To this end the permanent wall 14 is provided with vertically spaced horizontal rows of projecting supports which may be the bricks 19 although the invention includes within its scope other equivalent supporting members combined with masonry or other types of permanent walls. Each brick 19 (see the lowest brick of Fig. 2) is provided with an upper inclined plane face 20, an inner vertical plane face 21 and a rounded corner 22 at the meeting edge of the faces 20 and 21.

The permanent wall may be a bonded masonry wail, i. e. with its bricks including the bricks 19, bonded together by high temperature cement or fire clay. \Valls of this type, when subjected to high furnace temperatures deteriorate rapidly owing to the expansion and consequent compression, to which the bonded construction is subjected. The repair work on this type of masonry wall is not only difficult but is also slow and expensive. The inner facing 18 is composed of units, but instead of being a bonded masonry wall, is so constructed that no cement or bond is required between the individual bricks of the units. Moreover, provision is made for the expansion of each unit of the facing both horizontally and vertically. At the same time a free circuiation of air, confined to the space between the facing and the permanent wall is maintained. The facing supports 19 are special bricks bonded into the permanent wall at regular spaced intervals in selected tiers or courses thereof, to provide, behind the facing, air passages which may be arranged horizontally, as in Fig. 1, vertically as in Fig. 6, or any desired combination thereof as will be explained hereinafter.

\Vith this construction the inner surface 15 is protected from deterioration by the inner facing 18 which constitutes the first or main line of defense against the destructive heat of the furnace. The units of the facing 18 are free to expand in all directions without that compression which is characteristic of bonded masonry construction.

The wall supports 19 provide for the suspension of the lining or facing thereon, as shown best in Figs. 1 and 2. In building the lining, bricks are used having the novel characteristics shown in Figs. 10 and 11. Each horizontal row of the projecting supports 19, sustains a tier of lining bricks consisting of alternately arranged inter-engaging brick aprons 23 and 24. The relation of the vertical spacing of the horizontal rows of supports 19, to the vertical dimension of the suspended brick aprons 223 and 24, purposely is such that after successive tiers of the lining bricks have been suspended, a space or horizontal channel is left between each tier. These channels are filled, and the continuity of the lining is completed, by introducing in these channels alternately arranged inter-engaging filler bricks 25 and 26 (Figs. 5, 12 and 18).

The type of refractory lining just described in general terms, provides for ready removability and replacement of any tier, or of any portion of the lining as will be better understood from the following detailed description. It will be observed that the vertical rows of lining bricks, for example, a row composed of alternating brick aprons 23 and filler bricks 25, or of brick aprons 24 and filler bricks 26, produce a wall constructed of a series of adjoining vertical panels, that is, the vertical joints between the bricks in adjoining horizontal rows are not staggered as is customary in a masonry wall. This construction is particularly advantageous in repair work as will present- 1y be explained.

Each brick apron 23 (Fig. 10) comprises a 1 body 27 of the desired thickness, two inwardly facing side-flanges 28 and a rear bottomflange 29 depending from the body, and a suspension lug 30. The lug 30 is provided with a downwardly and outwardly inclined plane face 31 shaped to engage the inclined plane face 20 on the brick 19, a vertical plane face 32 shaped to engage the vertical face 21 on the brick 19, and a rounded internal corner 33, between the faces 31 and 32, shaped to engage the rounded external corner 22 on the brick 19. The bottom-flange 29 is provided with an inwardly facing inclined plane face 34. Attention is directed .to the fact that the top and bottom faces of the body portion 27 and the flange face 34 of the brick apron 23 are all oblique to the fri'nt face, the slope being outward and do nward after the brick is suspended on the orick 19. Each brick apron 24 is gener: .ly similar to the brick apron 23 except that the brick 24 is provided with outwardly facing side-flanges 35 instead of inwardly facing side-flanges making the suspension lug 38 narrower than the lug 30 on the brick 23. The internal corner of each of the sideflanges 35 may be provided with-a longitudinal groove 36 which, when provided, is packed with an asbestos rope 37 (see Figs. 3 and 4) or a mixture of clay and asbestos, or other resilient refractory material. Inclined plane top and bottom faces are provided on the body portion 37 of the brick 24 and an inwardly facing inclined plane face 39 on the depending rear flange 40 of the same obli uity as those of the brick 23.

In building a suspended tier or apron of the bricks 23 and 24 they are hung alternately by their rear lugs 30 and 38 on a row of the supports 19, the rear side flanges of the brick 24 overlapping the front sideflan es of the brick 23. The lugs 30 and 38 0 not interlock with the supports 19, but, as will be explained hereinafter, provision is made for permitting the bricks 23 and 24 to rock on the supports 19. The bricks 23 and 24 are not forced together tightly laterally, but are purposely hung with suflicient space left between them to allow for expansion (Figs. 3 and 4). The slip-type joints between the several inter-engaging fianges 28 and 35 may be sealed by the filling material 37 (Figs. 3 and 4).

To complete the continuity of the facing 18 the filler bricks 25 and 26 are seated in the horizontal channels already referred to, between the tiers of suspended bricks. Each filler brick 25 (Fig. 13) comprises a body 41 and a rear key member 42 the bottom face of which is flush with the bottom face of the body 41 but which is so proportioned as to be wider than the body portion. This provides two inwardly facing sidefian'ges 43. The width of the body 41 is the same as the width of the body or face of the suspended brick 23 since it is to be assembled in the vertical panel of which the suspended brick 23 forms a part. Likewise the width of the key member 42 is the same as the bottom flange 29 on the suspended brick 23. The continuity of the vertical faces of the panel is thus preserved. Each filler brick 25 is provided with a lower lane face 44 inclined to the plane of the ,ace of the lining which, as shown in Fig. 2, enga es the upper and similarly inclined plane face on the suspended brick 23. Each filler brick 25 is also provided with two upper inclined faces 45 and 46, the former, on the body 41, preferably being parallel to the lower face 44and the latter, on the key member 42, having a greater inclination and facing outwardly. When the filler brick 25 of one unit is seated on the suspended brick 23 of the same unit the upper face 45 is spaced from the inclined plane bottom face of the suspended brick 23 in the adjacent unit, and the outwardly facing upper face 46 is engaged with the inwardly facing inclined face 34 of the last mentioned suspended brick 23. Each filler brick 25 may desirably be provided with a horizontal groove 47 which is filled with asbestos or other flexible packing 48 (see Figs. 1 and 2) to seal the space between the engaging opposed body surfaces.

Each filler brick 26 (Fig. 12) has a body 49 equal in width to the face of the suspended brick 24 and its key member 50 is so proportioned as to provide two rearwardly facing side-flanges 51, this key being of the same width as the bottom-flange 40 on the suspended brick 24. This preserves the continuity of the vertical faces of the panel composed of the suspension bricks 24 and filler bricks 26. Each filler brick 49 has an inclined bottom face 52 and inclined top faces 53 and 54 of the same obliquity respectively as the analagous faces 44, 45 and 46 on the filler brick 25. Each filler brick 26 may desirably be provided with a horizontal groove 55 similar to the groove 47 on the filler brick 25. In addition the internal corner of each of the rear side flanges 51 may be provided with a vertical groove 56. The grooves 55 and 56 when provided, are filled with asbestos rope 48 and 57, or other flexible refractory packing.

In assembling the filler bricks with the aprons formed by the tiers of suspended bricks, first a filler brick 25 is placed between each pair of vertically adjacent bricks 23 of the several panels, and then a brick 26 is laced between each pair of vertically ad acent bricks 24 of the adjacent panels and so on until the facing is completed. The filler bricks of a row are retained in these spaces by reason of the obliquity of their seating, by the rearflanges 29 and 40, on the suspended bricks immediately above the filler bricks, which form rear stops, and by the overlapping of the side-fianges 43 and 51. The filler bricks 25 and 26 are not forced together tightly laterally, but are purposely hung with sufiicient space left between them to allow for expansion (Fig. 5). The sliptype joint between the flan es 43 and 51 is completely'sealed by the lling material 57 when used.

As clearly shown in Figs. 1 and 2 each unit of the facing comprises a suspended brick and a supported or filler brick. The upper downwardly and outwardly inclined plane surface of the supported brick in one unit is arranged parallel to the downwardly and outwardly inclined plane face on the bottom of the suspended brick immediately above it which, of course, is part of a different unit. This leaves a horizontal space (Fig. 1) between the opposed body portions of each unit. The rear upper downwardly and outwardly inclined plane face on the supported brick in one unit en- "ages the inwardly facing inclined plane face on the depending flange of the suspended brick immediately above it. The space 58 is completely sealed by the filiing material -18, when used (Figs. 1 and 2).

It will be apparent from an inspection of Figs. 2 and 4 that the length of the suspension lugs on the brick aprons 223 and 24 is such as to leave a space 59 between the rear face of the lugs and the outer wall 14. This space not oniy provides for expansion but permits considerable manufacturers tolerance in the construction of the bricks 23 and 24.

Referring again to Fig. 1 it will be noticed that the inclined plane faces on the bottom and rear-flange of the lowermost suspended brick in each panel are arranged, respectively, parallel and in engagement with inclined plane surfaces 60 and 61 formed on a bottom block 62 of the projecting bottom 17. The uppermost supported brick in each panel is spaced from and engages the topping block 63 on the overhanging top 16 like the spacing and en gagenient of the supported brick in one unit with the suspended brick in the next ver tic-ally succeeding unit.

With this construction the inner facing is held from vertical movement by the permancnt wall 1% which engages the inner facing at its top and bottom. But as the fac ing is composed of sections each of which engages the section immediately above it and immediately below it on inclined plane surfaces the height of the inner facing remains substantially constant during furnace temperature changes as the sections shift relatively on said inclined plane surfaces during the expansion and contraction of the bricks forming the inner facing.

It will be apparent to those skilled in the art that changes may be made in the direction and extent of the inclined plane surfaces between the sections of the inner facing to obtain various effects all within the scope of the present invention. For 1nstanee, the gap 58 may be dispensed with so that the supported brick in one unit and the suspended brick in the unit immediately above 1t engage on an inclined plane surface the full depth of the facing. prefer to employ the ap 58 because long inclined plane meeting aces on the supported brick in one unit and the suspended brick in another unit weakens the brick. By providing short inclined plane meeting faces and a gap 58 adjacent thereto the supported brick in one unit and the suspended brick in the unit immediately above said supported brick shift relatively during furnace temperature changes to provide for the free vertical expansion of the units of the facing in a reliable and certain manner. The slope of the inclined plane surface between the supported brick and the suspended brick in the same unit may be varied, or the said bricks may be amalgamated, so that the unit moves as an entity.

Referring again to Fig. 1 it will be apparent that when the bottom block 61 expands vertically pressure is brought to bear upon the inclined plane face on the depending flange of the suspended brick in the lowermost unit of one or more panels. This pressure causes the suspended brick in the lowermost unit to rock on its facing support 19 substantially at the point 64 (Fig. 2). The pressure of the supported brick, in each unit of the panel on the suspended brick in the unit directly above it causes each suspended brick to rock on its facing support 19 in a manner similar to the described rocking of the suspended brick in the lowermost unit. This rocking and the pressure between the supported brick in one unit and the suspended brick in the unit directly above produces a shifting of the sections of the facing laterally to maintain the height of the facing substantially constant during furnace temperature changes.

In the construction illustrated in Figs. 1 to 5 the bricks 19 abut and are, therefore, arranged in horizontal courses on the outer wall 14. This arrangement provides for a series of horizontal air passages 65 for the circulation of air between the surface 15 and the inner facing 18. his may be a forced circulation, if desired, the horizontal passages 65 being suitably connected to the usual intake and exhaust passages conveniently located in the wall 14.

In the construction illustrated in Figs. 6 to 9 the projecting bricks in each horizontal row on the outer wall 14 are spaced apart laterally forming separate suspension lugs 66 so as to provide vertical air passages 67 for the circulation of air between the surface 15 and the inner facing 18. This also may be a forced circulation, if desired, the vertical passages being suitably connected to the usual intake and exhaust passage 68 and 69 in the wall 14 (Fig. 6).

When the vertical air pass construction, illustrated in Figs. 6 to 9, is desired, suspension lugs 66, apron bricks 70 and 71 and filler bricks 72 are employed. So far as the trated in Figs. '6 to 9 is identical with that of the facing supports, apron bricks and the filler bricks illustrated in Figs. 1 to 5. The only difference between them is that the apron and filler bricks in the construction illustrated in Figs. 6 to 9 are enlarged at their rear ends to co-operate with enlarged heads on the lugs 66 and thus close up the openings which in Figs. 1 to 5 provide for the horizontal air passages. The apron bricks and the filler bricks in both constructions function identically.

B a judicious selection of the various kin s of supporting lugs, apron bricks and filler bricks, wholly vertical or wholly horizontal air passages may be built in the wall..

The size and spacing of the lugs'on the lining bricks and on the cooperating supporting bricks, both horizontally and vertically, are purposely designed and arranged as described so that it is only necessary to set out across the air space against the inner lining a suflicient number of the standard size fire bricks, from which the outer wall is built, to close any selected series of spaces between the lugs. Thus free and unobstructed air passages extending in any direction desired can be formed at will at very little expense since no extra shapes are necessary. Also, a wall thus constructed can readily be sectioned off in either direction as may be advantageous for a particular installation. For various reasons it is highly desirable to circulate more air through a certain area or section of the wall than through another section, and it is equally important to be able to change the circulation of air from horizontal to vertical, or viceversa, as this will avoid by-passing certain parts of the wall and result in an even cooling of the lining. The use of the resilient filling will prevent the air in this circulation or cooling chamber from passing through the facing to the combustion chamber.

Assuming that the lining has been in use and that a suspended brick, for example the central brick 23 of Fig. 1, has become cracked for some reason, a replacement would be made as follows: First the filler brick 26 above and to the left (or right) of the damaged brick is removed. The absence of cement and the shortkey member 50 of this filler brick permits it to be removed without displacing any adjacent brick. The filler brick 25 directly above the damaged brick may then be slipped sidewise, until its flange 43 is cleared of the next overlapping flange 51, and finally removed. Suspended brick 24 to the left (or right) of the damaged brick may then be forcedupward until its lug 38 is clear of the lugs 19, when it may be removed. This gives suflicient space to slide the damaged brick 23 sidewise to clear its flange 28 from the flange 35 on the adjoining suspended brick 24: whereupon it may be lifted from the supports 19 and removed. Replacement is accomplished by reversin' these steps. It will be observed that if a suspended brick 24 is damaged it may be removed and replaced. by taking out only the filler-brick above it. .Attention is especially called to the fact that the novel and improved furnace wall described, while of such thinness that it will heat and cool evenly, still provides ample constructional strength and yet successfully eliminates structural strains because of the provision for expansion of each unit of the wall both horizontally and vertically. All parts of the wall in large or small sections, are free to expand under heat, thus preventing spelling at any point on the wall surface however uneven the heat may be. The air space, per mitting free circulation of air in all directions behind the facing of refractory brick, is of importance because the thin bricks used may be thoroughly cooled by this circulation and thus still maintain their strength. Of equal importance under certain conditions are the sealed horizontal and vertical expansion joints which rovide for a continuity of the heat absorbing lining and also make a bonded brick construction unnecessary.

Particular attention is called to the highly advantageous feature of construction provided by the brick aprons which have been termed such because of their manner of support, but it should be distinctly understood that the invention is not limited to brick aprons suspended in the manner illustrated, but includes within its scope other means for removably sup orting the facing wall bricks in spaced re ation to the permanent furnace wall. Accordingly, in the appended claims characterizing features of the invention are set forth by the intentional use of generic terms and expressions inclusive of various modifications.

The nature and scope of the invention having been indicated, and its preferred embodiments having been specifically described, what is claimed as new, is

1. In a furnace wall construction a permanent wall, a facing therefor, and means on the permanent wall engaging the top and bottom of the facing, said facing from top to bottom comprising a plurality of sections at least one of which engages the section immediately above it and immediately below it on inclined plane surfaces whereby said adjacent sections may shift relatively on said surfaces to maintain the height of the facing substantially constant durinlg furnace temperature changes.

2. n a furnace wall construction a permanent wall, and an inner facin spaced from said permanent wall, said facing comprising a plurality of sections. some of which are suspended from the permanent wall and some of which are supported entirely by the suspended sections, at least one of said sections engaging the section immediately above it and immediately below it on inclined plane surfaces whereby said adjacent sections may shift relatively on said surfaces during furnace temperature ehan es.

3. In a furnace wall construction a permanent wall, and an inner facing spaced from said permanent wall, said facing comprising a plurality of sections some of which are suspended from the permanent wall and some of which are supported entirely b the suspended sections, at least one of sai sections engaging the section immediately above it on inclined plane surfaces havin a width less than the thickness of the section whereby the said adjacent sections may shift relatively on said surfaces during furnace temperature changes, there bemg a space between the opposed portions of the sections adjacent the inclined plane surfaces to allow the sections to so move relatively.

4. In a furnace wall construction a permanent wall, an inner facing spaced from said permanent wall, said facing comprising a plurality of sections at least one of which engages the section immediately above it and immediately below it on inclined plane surfaces whereby the section may slide on said inclined surfaces during furnace temperature changes, and means for pivotally suspending the sections above and below said section, on which it slides, from said permanent wall to permit said suspended sections to rock while the intermediate section slides.

In a furnace wall construction a permanent wall, and an inner facing spaced from said permanent wall, said facing comprising successive rows of brick units each unit comprising one brick suspended from a built-in support on said permanent wall and one brick cuneiform in formation above and wholly supported by the suspended brick, the cuneiform brick in one unit having engagement with the suspended brick in another unit immediately above it.

6. In combination with a permanent furnace wall, an inner lining therefor constructed of successive rows of brick units each unit comprising one brick suspended from a built-in support on the inner face of the permanent wall and one brick above and wholly supported by the suspended brick, the supported brick and the suspended brick in one unit having abutting downwardly and outwardly inclined piano surfaces and the supported brick in one unit and the suspended brick in another unit adjacent thereto having abutting inclined plane surfaces.

7. In combination with a permanent furnace wall, an inner lining therefor constructed of successive rows of brick units each unit comprising at least two bricks,

means for suspending one brick of the unit from the permanent wall, with another brick of the unit above and wholly supported by the suspended brick, there being an inclined slip-type joint between the supported brick in one unit and the suspended brick in another unit adjacent thereto.

8. In combination with a permanent furnace wall, an inner lining therefor constructed of successive rows of brick units each unit comprising at least two bricks, means for suspending one brick of the unit from the permanent wall, with another brick of the unit above and wholly supported by the suspended brick, there being a vertical space and an inclined slip-type joint be tween the supported brick in one unit and the suspended brick in the unit above said supported brick.

9. In combination with a permanent furnace wall, an inner lining therefor constructed of successive rows of brick units each unit comprising at least two bricks, means for suspending one brick of the unit from the permanent wall, and another brick of the unit resting on and wholly supported by the suspended brick, the abutting faces of the supported and suspended brick in one unit being oblique to the lane of the lining in such a direction that t e supported brick gravitates outward when seated on the suspended brick, there being an inclined slip-type joint, sloping in the same general direction as the abutting faces of the supported and suspended brick, between the supported brick in one unit and the suspended brick in another unit adjacent thereto.

10. In combination with a permanent furnace wall, a refractory lining comprising successive horizontal, vertically spaced single rows of brick suspended rom the permanent wall, each suspended brick having its upper ed e face in a plane that slopes downwardly and outwardly and having also a lower depending flange provided with a face in a plane that slopes downwardly and outwardly, and rows of filler brick seated loosely in said spaces, each filler brick hav ing a lower edge face in a plane to engage said sloping upper edge face on the suspended rick and an upper edge face in a plane to engage said sloping face on the depending flange of the suspended. brick.

11. In combination with a permanent furnace wall, an inner lining therefor con structed of successive rows of brick units each unit comprising at ieast two bricks, means for suspending one brick of the unit from the permanent furnace wall constructed to permit the suspended brick to rock thereon, and another unbonded brick of the unit resting on and wholly supported by the suspended brick when it rocks.

12. In combination with a permanent furnace wall, an inner lining therefor constructed of successive rows of brick units each unit comprising at least two bricks, means for suspending one brick of the unit from the permanent furnace wall constructed to permit the suspended brick to rock thereon, and another brick of the unit resting on and wholly supported, by the suspended brick, there being a diagonal sliptype joint between the supported brick in one unit and the suspended brick in another unit adjacent thereto.

13. In combination with a permanent furnace wall, a refractory lining comprising successive horizontal, vertically spaced complete rows of bricks each row being one brick in height, means for suspending each brick from the permanent wall constructed to permit each brick to rockthercon, and a complete row of filler brick seated loosely in each of said spaces.

14. A furnace wall construction comprising a permanent wall having a plurality of built-in projecting supports and an inner lining therefor constructed of successive rows of brick units each unit comprising one brick suspended to rock on one of said supports and provided with an upper inclined plans surface and a lower depending flange having an inclined plane face and another brick resting on and wholly supported by the upper inclined plane surface on the suspended brick, the supported brick in one unit having an inclined plane face engaged with the inclined plane face on the depending flange of the suspended brick in another unit adjacent thereto.

15. A furnace wall having an outer wall provided with forwardly projecting lugs in horizontal rows each lug having an upper inclined plane surface, an adjacent vertical plane surface and a rounded meeting corner between said surfaces, and an inner lining comprising vertically spaced substantially horizontal rows of bricks suspended from said outer wall lugs by at least one depending lug on each brick provided with a lower inclined plane surface engaged with the upper inclined plane surface on the outer wall lug, an adjacent vertical plane surface engaged with the vertical plane surface on the outer wall lu and a rounded surface,

engaged with the rounded corner on the outer wall lug.

16. In a furnace wall a heat-resisting facing comprising a plurality of refractory suspended bricks and a plurality of refrac tory filler bricks, each filler brick being located vertically between two suspended bricks, and the abutting faces of said filler and suspended bricks both above and below each filler brick being oblique to the plan of the facing in such a direction that while the filler bricks tend to gravitate outward when seated they are held in the plane of the facing between each of said two suspended bricks.

17. In a refractory lining for furnace walls a row of bricks comprising successive pairs of bricks arranged horizontally, each pair composed of one brick having two front side flanges and one brick having two rear side flanges whereby the adjacent side faces of each two adjoining bricks are lapped after assembly and material interposed between the internal corner of one flange and the external corner of the other flange for sealin the joint therebetween.

18. n a refractory lining for furnace walls a row of bricks comprising successive pairs of bricks arranged horizontally, each pair composed of one brick having two front side flanges and one brick having two rear side flanges whereby the adjacent side faces of each two adjoining bricks are lapped after assembly, one pair of said side flanges havin vertical rooves in the internal corners tIrereof, an sealing material filling in the grooves.

19. In combination with a permanent furnace wall, an inner lining therefor constructed of successive rows of brick units each unit comprising one brick suspended from a built-in sup ort on the inner face of the permanent wal and another brick resting on and wholly supported by the suspended brick, the supported brick in one unit and the suspended brick in another unit adjacent thereto havin substantiall parallel inclined plane sur aces spaced rom each other, one of said surfaces having a horizontal groove, and sealing material in the groove.

20. In a furnace wall a heat resisting inner facing comprising successive horizontal rows of refractory units providing sections separated by horizontal expansion joints and packing between the opposing surfaces of said sections above and below each joint, said packing consisting of material capable of (yielding to accommodate expansion of sai facing units.

21. A furnace wall construction comprising a spaced rom said permanent wall providing an air circulation passage between said facing and the inner surface of said permanent wall, said inner facing comprising unbonded refractory bricks and having provision for expansion of its bricks in all directions, and yielding means at the meeting faces of said bricks to seal said circulation passage from the furnace heat and to accommodate said expansion.

22. In combination with a permanent furnace wall an inner refractory linin constructed of successive complete rows 0 brick units each composed of two unbonded bricks of which the lower is supported by the permanent wall and the upper: is supported ermanent wall, an inner facinglib wholly by the lower, the bricks of said units being so shaped and engaged with each other as to pivot and shift relative t0,each other to relieve the strain between the units due to expansion when subjected to heat, there being also slip-type vertical joints between adjacent units.

In testimony whereof I afiix my signature.

OSCAR N YGAARD.

wholly by the lower, the bricks of said units being so shaped and engaged with each other as to pivot and shift relative topaoh other to relieve the strain between the units due to expansion when subjected to heat, there being also slip-type vertical joints between adjacent units.

In testimony whereof I aiiix my signature.

m OSCAR NYGAARD.

CERTIFICATE OF CORRECTION.

Patent No. 1,807,929. Granted June 2, 1931, to

DSCAR NYGAARD.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 1, line 65, for the word "opposite" read opposed; page 6, line 128, claim ll,ior the words "wholly supported" read shiftable; page 7,. line 29, claim 14, for "plans", read plane; and that the saicLLetters Patent should be read with these corrections therein that the mac may conform to the record of the case in the Patent Office.

Signed and sealed this 4th day of August, A. D. 1931.

Wm. A. Kinnan, (Seal) Acting Commissioner of Patents.

CERTIFICATE OF CORRECTION.

Patent No. 1,807,929. Granted June 2, 1931, to

OSCAR NYGAARD.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page I, line 65, for the word "opposite" read opposed; page 6, line 128, claim ll,lor the words "wholly supported" read shiftable; page 7,, line 29, claim 14, for "plans", read plane; and that the said Letters Patent should he read with these corrections therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 4th day of August, A. D. 1931.

Wm. A. Kinnan, Acting Commissioner of Patents. 

